This artist’s concept depicts in the foreground planet Kepler-62f, a super-Earth-size planet in the habitable zone of its star which is seen peeking out from behind the right edge of the planet. The small shining object farther to the right is Kepler-62e which orbits on the inner edge of the habitable zone of the star. Credit: NASA/Ames/JPL-Caltech.

Exoplanets have found a permanent place in the public imagination, probably because of the possibility of finding an Earth twin: a planet where life as we know it (either extraterrestrial or, eventually, our own) could survive. While we’re not there, yet, a NASA press conference today suggests we’ve come closer to this goal: the first known planets that could plausibly support life.

A nearby star named Kepler-62 turns out to harbor five worlds, two of which are the smallest exoplanets known to orbiting within their star’s habitable zone. This means temperatures on them would allow for liquid water to exist (a requirement for life). In fact, scientific models suggest that both could be “water worlds,” completely covered with global oceans. “These two planets are our best candidates for planets that might be habitable,” said William Borucki, Kepler science principal investigator, at the conference.

The two new exoplanets, known as Kepler-62e and Kepler-62f, are the farthest out of the five that orbit Kepler 62, a star smaller and cooler than the sun that lies about 1,200 light-years away. The radius of Kepler-62e is about 60 percent bigger than Earth’s, and it takes about 122 days to orbit its star. Kepler-62f’s radius is only about 40 percent larger than Earth’s, and its year lasts some 267 days.

The conference also announced a third intriguing exoplanet, Kepler-69c, which orbits within the habitable zone of its star, Kepler-69 (a sun-like star about 2,700 light-years away). This world has a radius 70 percent larger than Earth’s and orbits its star in 242 days.

The masses of these planets are too small for scientists to measure, so scientists can only speculate as to their makeup at this point, but every other known exoplanet of similar size has turned out to be rocky, similar to Earth. The Kepler-62 planets were reported today in Science and Kepler-69c today in The Astrophysical Journal.

Astronomers found these worlds thanks to NASA’s Kepler spacecraft, which launched in 2009 specifically to seek out Earth-like exoplanets. It searches for stars with occasional dips in brightness, potentially caused by an exoplanet crossing its shining face. From that minor dimming, akin to a fly buzzing in front of a car’s headlight, astronomers can piece together a surprising amount of information.

Kepler’s impressive and prodigious results (more than 2740 planet candidates found so far) have never before included candidates so close to an Earth twin, but with any luck, and more research, they soon will.

“We are on the verge of the discovery of so many very exciting planets!” said Lisa Kaltenegger of the Harvard-Smithsonian Center for Astrophysics at the conference.

“Nearby” is a relative term in astronomy. On the scale of the Milky Way Galaxy, every single star observed by Kepler counts as “nearby”.

Davis Mann

Because they said so. They -(NASA, among other exceptional individuals/organizations)- have the means (genius) to discover, discern, and calculate many of space’s referenceless mysteries and applied the rigidities of science to the vastness of space [thought/proven to be…incomprehensible to all but that handful we’re graced by, and to whom I advice to provide benefit of doubt.

I am decently educated (by US standards, so- grain of salt…:), and I didn’t want to hit you with the numbers- in hopes that my appeal to just “trust” might suffice; however- you’ve “read” too much to give up that easily. You’ve “read,” and seem to have some conceptual basis for:
a.) the vastness of space
b.) unit of such measurement
c.) findings of NASA’s habitable planetary search- for lack of better, or coined, term)
d.) Tight grasp of >, =, AND < signs!

No avid reader on the subject, I stumbled upon this article, so please excuse me if incorrect…
I'm no scientist, astronomer, or physicist.

* Here's my point: I think this is all in the name of discovery, and in so- to collect data, theorize, and essentially get the gears moving on solving issues of making feasible the task of accomplishing manned missions which travel beyond our current understanding.

Curiosity, anxiety/paranoia, and foresight drive us to find the "What" (habitable planets…for resources, discovery of life, mitigation of hostilities…etc). Who, what, when, where, why, or of what means we will discover the "How" that hovers over all of these "conditional successes" will make your issue of exoplanets' relative distances from Earth and eachother of little concern. The veil of space/time must be breached to viably attempt transit to a place even "as close" as Gliese- that is, unless it's a one-way trip, with supplies to live from exclusively and indefinitely.

They're searching, not to find a planet "habitable," so much as inhabited…

Arlin Jordan

I wanna go………

John

I want to go, too!

gendotte

So now we need to get Doc Smith back to explain how to design an inertialess engine.

yvessaintdid@gmail.com

It’ll be like hopping from stone to stone to cross a river. We go to one like Gliese 581 first and continue moving outwards. We’ve got to be chill about it though, cos it’s going to take vast lengths of time.

Peristroika

Kay, so the problem with basic propulsive methods is that it’s nearly impossible without fusion or antimatter to hold enough propellant to gain enough speed to enter time dilation and last for the length of journey. What if instead of basic mass being thrust out the back, we use inertial mass? If the spaceship is basically a huge particle accelerator, then by shooting the particles out the nozzle at near light speed, you’ve effectively increased the mass exiting and therefore the nudge forward. All at the expense of a single particle. Wouldn’t this allow 3 ounces of matter to be converted to many tonnes of accelerant? It only takes a month at one G to achieve a large percentage of light speed!

James Shaffer

If NASA would have paid attention to my theories on travel through space via sub-sonic, and the use of particular oscillating audio wave frequencies, a paper I submitted to them in 1978, we might be flying around those worlds right now instead of looking at them through a telescope, and wandering why we are not there. I was laughed at for my theories, but guess what NASA is studying now?? Right!! Travel through space using sub-sonic theories!! Good thing I saved my paper!! James Shaffer